Detect server name in PHP

Question

I have a number of instances behind a loadbalancer. Is it possible to detect the name of the machine (e.g. ec2-XXX-XX-XXX-XXX.compute-1.amazonaws.com) in PHP for debugging? I looked through phpinfo() and it doesn't seem to have any kind of machine specific information.

Answer 1

you'll have to use $host = system("hostname") or similar as it appears PHP won't provide that info directly.

IP seems a little more involved. Depends on how they've got things set up but you can try

$config = system("ifconfig | grep \"inet addr\"");
preg_match("/(\d{1,3})(\.\d{1,3})/", $config, $matches);
$ip_addr = $matches[1];

Answer 2

This should do it:

http://php.net/manual/en/reserved.variables.server.php

$myservername = $_SERVER['SERVER_NAME'];

Answer 3

IIRC, the public hostname actually doesn't exist anywhere on the server. It's stored in EC2's metadata, which can be fetched from 169.254.169.254 on any EC2 instance.

$hostname = file_get_contents('http://169.254.169.254/latest/meta-data/public-hostname/');